Enhancing Flexibility with Vibration and Stretching: New Research Validates ProbeFix in Dynamic Ultrasound Imaging

At Usono, we’re always excited to see our innovations contribute to cutting-edge research in sports science and rehabilitation. A recent study published in the European Journal of Applied Physiology highlights the role of vibration and stretching in improving flexibility. This showcases how our ProbeFix Dynamic enabled precise, reproducible ultrasound imaging with with SuperSonic Imagine Aixplorer ultrasound machine.

Study Overview: Stretching, Vibration, and Flexibility

Immediate effects of passive stretching and/or local vibration on ankle range of motion, calf muscle stiffness and passive torque: a randomized controlled cross-over trial

We recently spoke with first author Daniel Jochum about this interesting scientific work on the influence of vibration, which reduces joint resistance. This could improve compliance in populations who avoid stretching due to discomfort, such as older adults or post-injury patients. For rehabilitation vibration could offer a non-invasive adjunct to stretching, especially where stiffness or joint resistance impairs movement (e.g., after immobilization).

Summary from the First Author

Flexibility is considered of fundamental importance in sports, health and rehabilitation settings and is associated with increased performance as well as reduced injury risk. While stretching as a stand-alone intervention is the most common training method to increase joint range of motion (ROM), our own recent meta-analysis suggested vibration to be an effective alternative.

We wondered if the combination of vibration and stretching might accumulate their effects. Also, the mechanisms behind vibration-induced flexibility gains are still unclear.

Therefore, the objective of this study was to investigate the specific effects of two minutes of stretching with and without superimposed vibration on ankle ROM, ankle passive torque over the whole ROM, and gastrocnemius medialis muscle stiffness. The stretching interventions were also compared to vibration alone as well as a passive control condition.

ProbeFix in Action: Reliable Ultrasound Imaging During Movement

The Con-Trex isokinetic dynamometer was used to assess ankle dorsiflexion ROM and passive resistive torque during passive dorsiflexion. The foot of the participant was fixed with straps to the machine, while we also fixated an Aixplorer ultrasound scanner with the ProbeFix to the gastrocnemius medialis to assess muscle stiffness during the whole procedure.

The ProbeFix was chosen to ensure reproducibility and objectivity, as the ultrasound probe was consistent in the same position on the muscle. Further, we were able to conduct rapid measurements due to the stable image of the ultrasound device. This hands-free solution enabled dynamic imaging during pre- and post-testing as well as during the interventions.

Key Findings

• All interventions significantly increased ROM compared to the passive control group.
• Muscle stiffness decreased in all conditions.
• Stretching combined with vibration produced the most pronounced reductions in passive torque.

In conclusion, vibration is not superior to stretching but might be used as an alternative to increase ROM immediately and is potentially interesting as a warm-up in the resting condition. Though the superimposition of vibration to stretching did not further increase ROM, the combination of both interventions presented the most prominent influence on joint resistance. This might be interesting for practitioners who struggle with progress in flexibility performance using conventional stretching exercises.

Vibration also increases stretching pain tolerance, which might facilitate the conduction of exercises and improve compliance as well as adherence to stretching habits.

As vibration affects joint resistance rather than muscle stiffness, other structures might be affected, e.g., tendons or the muscle-tendon junction. Therefore, this calls for further research on this interesting topic.

Why This Matters for Usono

This study is a great example of how ProbeFix empowers researchers and clinicians to perform dynamic, hands-free ultrasound imaging with high reproducibility. Whether in sports science, rehabilitation, or clinical diagnostics, our solutions are designed to support innovation and improve outcomes.

Want to learn more about ProbeFix or explore how it can support your research or clinical practice?

Get in touch with us or explore ProbeFix to see how we can help you bring ultrasound imaging to the next level.

Full publication

Link to the original full publication: https://link.springer.com/article/10.1007/s00421-025-05839-6